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<html lang="en">
	<head>
		<title>three.js webgl - custom attributes [particles]</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<style>
			body {
				color: #ffffff;
				font-family:Monospace;
				font-size:13px;
				text-align:center;
				font-weight: bold;

				background-color: #000000;
				margin: 0px;
				overflow: hidden;
			}
			#info {
				color: #fff;
				position: absolute;
				top: 0px; width: 100%;
				padding: 5px;
				z-index:100;
			}
			a { color: #ff0000 }
		</style>
	</head>

	<body>
		<div id="info"><a href="http://threejs.org" target="_blank" rel="noopener">three.js</a> - custom attributes example - particles</div>
		<div id="container"></div>

		<script src="../build/three.js"></script>

		<script src="js/WebGL.js"></script>
		<script src="js/libs/stats.min.js"></script>

		<script type="x-shader/x-vertex" id="vertexshader">

			uniform float amplitude;
			attribute float size;
			attribute vec3 customColor;

			varying vec3 vColor;

			void main() {

				vColor = customColor;

				vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );

				gl_PointSize = size * ( 300.0 / -mvPosition.z );

				gl_Position = projectionMatrix * mvPosition;

			}

		</script>

		<script type="x-shader/x-fragment" id="fragmentshader">

			uniform vec3 color;
			uniform sampler2D texture;

			varying vec3 vColor;

			void main() {

				gl_FragColor = vec4( color * vColor, 1.0 );
				gl_FragColor = gl_FragColor * texture2D( texture, gl_PointCoord );

			}

		</script>


		<script>

		if ( WEBGL.isWebGLAvailable() === false ) {

			document.body.appendChild( WEBGL.getWebGLErrorMessage() );

		}

		var renderer, scene, camera, stats;

		var sphere;

		var WIDTH = window.innerWidth;
		var HEIGHT = window.innerHeight;

		init();
		animate();

		function init() {

			camera = new THREE.PerspectiveCamera( 40, WIDTH / HEIGHT, 1, 10000 );
			camera.position.z = 300;

			scene = new THREE.Scene();

			var amount = 100000;
			var radius = 200;

			var positions = new Float32Array( amount * 3 );
			var colors = new Float32Array( amount * 3 );
			var sizes = new Float32Array( amount );

			var vertex = new THREE.Vector3();
			var color = new THREE.Color( 0xffffff );

			for ( var i = 0; i < amount; i ++ ) {

				vertex.x = ( Math.random() * 2 - 1 ) * radius;
				vertex.y = ( Math.random() * 2 - 1 ) * radius;
				vertex.z = ( Math.random() * 2 - 1 ) * radius;
				vertex.toArray( positions, i * 3 );

				if ( vertex.x < 0 ) {

					color.setHSL( 0.5 + 0.1 * ( i / amount ), 0.7, 0.5 );

				} else {

					color.setHSL( 0.0 + 0.1 * ( i / amount ), 0.9, 0.5 );

				}

				color.toArray( colors, i * 3 );

				sizes[ i ] = 10;

			}

			var geometry = new THREE.BufferGeometry();
			geometry.addAttribute( 'position', new THREE.BufferAttribute( positions, 3 ) );
			geometry.addAttribute( 'customColor', new THREE.BufferAttribute( colors, 3 ) );
			geometry.addAttribute( 'size', new THREE.BufferAttribute( sizes, 1 ) );

			//

			var material = new THREE.ShaderMaterial( {

				uniforms: {
					amplitude: { value: 1.0 },
					color: { value: new THREE.Color( 0xffffff ) },
					texture: { value: new THREE.TextureLoader().load( "textures/sprites/spark1.png" ) }
				},
				vertexShader: document.getElementById( 'vertexshader' ).textContent,
				fragmentShader: document.getElementById( 'fragmentshader' ).textContent,

				blending: THREE.AdditiveBlending,
				depthTest: false,
				transparent: true

			} );

			//

			sphere = new THREE.Points( geometry, material );
			scene.add( sphere );

			//

			renderer = new THREE.WebGLRenderer();
			renderer.setPixelRatio( window.devicePixelRatio );
			renderer.setSize( WIDTH, HEIGHT );

			var container = document.getElementById( 'container' );
			container.appendChild( renderer.domElement );

			stats = new Stats();
			container.appendChild( stats.dom );

			//

			window.addEventListener( 'resize', onWindowResize, false );

		}

		function onWindowResize() {

			camera.aspect = window.innerWidth / window.innerHeight;
			camera.updateProjectionMatrix();

			renderer.setSize( window.innerWidth, window.innerHeight );

		}

		function animate() {

			requestAnimationFrame( animate );

			render();
			stats.update();

		}

		function render() {

			var time = Date.now() * 0.005;

			sphere.rotation.z = 0.01 * time;

			var geometry = sphere.geometry;
			var attributes = geometry.attributes;

			for ( var i = 0; i < attributes.size.array.length; i ++ ) {

				attributes.size.array[ i ] = 14 + 13 * Math.sin( 0.1 * i + time );

			}

			attributes.size.needsUpdate = true;

			renderer.render( scene, camera );

		}

	</script>

</body>

</html>
